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United States Patent | 5,740,153 |
Ohta ,   et al. | April 14, 1998 |
A magneto-optical disk including a transparent substrate, pit strings containing information formed in spiral or concentric form on a surface of the transparent substrate, a magneto-optical recording medium layer for covering the surface of the transparent substrate having the pit strings formed thereon, and magneto-optical recording areas formed by spiral or concentric flat portions between adjacent pit strings. An optical pickup for reproducing pit information and magneto-optically-recorded information from the magneto-optical disk. A magneto-optical disk drive for recording and reproducing information on the magneto-optical disk. The magneto-optical disk has a memory capacity which is twice the memory capacity of a conventional magneto-optical disk having ROM, and is accessed at high speeds.
Inventors: | Ohta; Kenji (Kitakatsuragi-gun, JP); Terashima; Shigeo (Tenri, JP); Takahashi; Akira (Nara, JP) |
Assignee: | Sharp Kabushiki Kaisha (Osaka, JP) |
Appl. No.: | 801245 |
Filed: | February 19, 1997 |
Jun 29, 1993[JP] | 5-158871 |
Current U.S. Class: | 369/275.2; 369/13.35 |
Intern'l Class: | G11B 007/24 |
Field of Search: | 369/275.1,275.2,275.3,32,13,116,44.23,44.24,124,112,110,109 |
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5554436 | Sep., 1996 | Katayama et al. | 369/13. |
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